As NPR's Carrie Johnson reports, under the charge of using weapons of mass destruction, which is the core of Monday's indictment against Tsarnaev, he is eligible for the death penalty.

Determining that is "a really long process which involves a special committee at the Justice Department and approval from the attorney general himself," she says.

Rosanna Cavallaro, a professor at Suffolk University Law School, says the threat of a death penalty could prove "a very powerful tool in terms of leveraging cooperation from this defendant to get him to be forthcoming not only in terms of how these crimes were carried out but about things that go beyond the events, such as possible communications with other groups."

So far, there appears to be little evidence that Tsarnaev, an ethnic Chechen who is a naturalized U.S. citizen, had links to terrorist groups inside or outside the United States, but Johnson says authorities "are still investigating. They are gathering a lot of evidence at crime scenes, processing forensics, trying to trace these guy's movements both online and physically."

Getting the kind of information that could definitively answer questions about Tsarnaev's motive and possible ties could become part of a plea deal, according to Cavallaro.

"That's a difficult call," she says. "There's a certain value in allowing a community to go through a trial to revisit the experience and to feel a complete sense of transparency and clarity," she says, adding that a trial would nonetheless prove painful ordeal for Boston. "A plea would be a way of avoiding that pain."

Jeffrey Addicott, the director of the Center for Terrorism Law at St. Mary's University in San Antonio, Texas, thinks a plea deal is unlikely.

"The case is too large and high profile – the bombing itself, the manhunt and the shooting spree - it's all just too big," he says. "I just don't see the Department of Justice being willing to accept a plea bargain."

Gregory McNeal, a professor at Pepperdine University School of Law, also thinks that "unless there's some compelling evidence that these guys did not act alone, I can't see the government taking the death penalty off the table.

There's also the question of venue. Could Tsarnaev ultimately get a fair trial in Boston?

"It's very difficult if impossible to have a trial unfold here in the city of Boston," says Cavallaro. "Nearly everyone that I've spoken to here has been in some way touched by this – obviously some people touched much more directly by injury or loss, but when you factor in that six degrees of separation nearly everyone knows someone very well who was hurt or injured or was in law enforcement."

But that presents logistical headaches. Many witnesses will be in Boston and in a trial that would likely to take weeks or month, any change of venue could become a burdenl, she says.

Addicott agrees. He thinks the defense would pursue a change of venue but that given the nature of the crime and its saturation coverage by the media, no judge would grant one.

"The defense counsel, their strategy is going to be to delay, call for a change of venue and hope for a technicality," he says. "They are going to hope the government doesn't cross a 't' or dot an 'i' and then use that to try to get a lesser sentence on appeal."

McNeal says the swiftness with which the indictment came down proves the superiority of the civilian legal system to deal with such cases, despite calls over the weekend by Republican Senators Lindsey Graham and John McCain for Tsarnaev to be treated as an enemy combatant.

Pointing to the glacial slow progress of the military case against Khalid Sheikh Mohammed, the alleged mastermind of the Sept. 11, 2001 attacks, McNeal says: "If this were a military tribunal, we'd still be waiting for a criminal complaint two years from now," he says.